Yep, just by disconnecting your router, waiting 15 seconds and plugging it in again just clears their IP ban with a new IP.
I use Logician's Hellban hack. However, you will have to PM him on theadminzone.com, that's how I got it. I usually just use bans (permanent bans) and anyone I have banned doesn't come back until the ban expires.
If you still can't keep out dupe accounts, then find out the ISP of the user and contact the ISP about it.
|